The Emmy-nominated TV personality, who hosted Dancing with the Stars for eight seasons, is a certified personal trainer and has graced the cover of a number of fitness magazines. So when she felt a lump in her breast at age 40, her doctors told her not to worry—but Harris’ gut instinct told her otherwise.

“That’s when I went to see a surgical oncologist,” says Harris. “I really didn’t think I had cancer.”

After a needle biopsy, two ultrasounds and an MRI, the only oddity that came up was an irregular clump of cells. The oncologist took it out just to be safe—and found that it was invasive ductal carcinoma. Harris followed the diagnosis with a double mastectomy and reconstruction.

“2014 was a pretty awful year of surgery and recovery, but I found that even though I was blindsided and sidelined, I didn’t let the cancer devour me,” says Harris. “Instead, it ignited something so powerful in me that it compelled me to find out how to live a much healthier life and share it with others.”

The result? Her book, Your Healthiest Healthy, a guide that will help you overhaul your lifestyle to prevent and treat cancer and other chronic diseases.

Parade chatted with Harris about her book, life after cancer and the steps you can take today to cut your cancer risk.

Tell us a little about the book.

It’s called Your Healthiest Healthy, and it is the guide that I wish so much that someone had given me after my breast cancer diagnosis—or before it because hopefully it would have allowed me to never be diagnosed with breast cancer. It’s all about the changes we can make in our lives to take control and live our healthiest life ever to prevent and avoid not just cancer but also other chronic diseases like Type 2 diabetes and heart disease. I searched for a book when I was diagnosed, and it just didn’t exist.

The book includes a lot of research. What’s one of the most interesting things you uncovered as you were writing it?

I was really surprised at how much the food industry hides and markets ingredients to play up certain ingredients as lifesavers that aren’t necessarily so great when they’re loading it down with hidden sugars. Learning how to read an ingredient label the proper way, not just looking at it for fat content and calories, but truly understanding what the ingredients are that are going into the foods that I was eating, how many different words the food industry has for sugar to fool us as consumers. I really started to lean into a much more plant-based, whole foods lifestyle, trying to cut down on the amount of processed food I was eating, cut down on animal protein. That was one of the biggest nutritional surprises. Then the other biggest surprise was how many chemical ingredients are in our beauty products and our household cleaners. We’re allowed to go to the store and buy them and the FDA has approved them, so they must be safe for us, or so we think. As a consumer, I was fooled to think that our government totally has our back when there’s strong lobbyists in that industry, especially the beauty industry and the food industry, that are lobbying and allowing their pockets to be filled to such an extreme that it ends up to our health detriment.

Making changes for myself, which was the focus, the benefit has been that it is helping my family. I have two little girls who are 7 and 11, and being able to give them a leg up and get these toxic products out of our house. Being able to, as my girls end up entering puberty, learning about feminine products and how many toxins, between the bleach and dioxins, are in our tampons and feminine pads, and knowing that I can hand it over to them and they can be safe and take care of their newfound womanhood.

Do you have a favorite section of the book?

I would have to say it’s chapter three, which is the toxins in our beauty products and our household cleaners because. Especially for someone who has had a career in TV where I find myself in the makeup chair day in and day out, it was one of the most impactful changes, being able to clean up my beauty routine and learn about what ingredients I want to avoid. I was actually looking at creating my own beauty line because I wasn’t sure there was enough out there that could have the staying power that we need for TV. Thankfully I’ve been able to discover that there are a lot of wonderful clean brands out there because the demand is getting higher. We, as consumers, are going to take control with our consumer dollars and put that money toward products that are healthier and safer for not only us but also for our environment.

How did cancer change your perspective?

I’d always been an overly positive person, and cancer definitely stole that for a short time. I realized that I have the ability to consiously change my perspective, which can change your overall demeanor and well-being. While I was curled up in a ball for the first couple of weeks after my diagnosis, I knew it was going to be a long journey, so I made that conscious choice to take on every bit of information that came at me with a positive spin. Just making that conscious, mental switch really helped me not only get out of bed and be there and present and active for my girls and my husband, but also to be a calmer person going through this.

How’s life now?

Life is incredible. I’m more energized than I’ve ever been, and I really attribute that to the nutritional changes, being more plant-based, whole foods and filling my plate up with vegetables—at least half full of vegetables at every meal, including my morning smoothie. But all the changes I made were in very small steps over the last four years, and it’s a continuing journey. I feel more fit than I’ve ever been. I just finished my first ever endurance hiking challenge where, over the course of 36 hours, I hiked 23 miles at a 23 foot incline. It’s been a great rebirth.